/**
 *  Copyright (C) 2013  Piotr Szczepa�ski
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
package edu.pw.elka.gtsna.graph_creator;

import edu.pw.elka.gtsna.graph.Edge;

/**
 * @author Piotr Lech Szczepa�ski
 * @author P.Szczepanski@ii.pw.edu.pl 
 *
 */


/**
 * generate a random graph that is a tree. This graph is constructed by
 * attaching each new agent to a single randomly picked existing agent.
 */
public class TreeGraphGenerator extends RandomGraphGenerator {


	public TreeGraphGenerator(int numOfNodes) {
		super(numOfNodes);
		
		//node i=1 is the root, and so it is not connected to any other node.
		//node i>1 is connected to a random node in [0, ..., i-1]
		for(int i=2; i<=numOfNodes; i++)
		{
			int j = random.nextInt(i-1) + 1; //to get a random number in [1,i-1]
			edges.add(new Edge(i,j));
		}		
	}


}
